Pile hammer and like percussion machine



Oct. 19, 1954 N. G. BELL PILE HAMMER AND LIKE PERCUSSION MACHINE FiledSept. 9, 1949 4 2 7//// //7/// PU. -s H m 7//7///Z H m m l h m 1 h a hUV G. Z H q 5 u z Attorney Patented Oct. 19, 1954 UNITED STATES PATENTOFFICE PILE HAMMER AND LIKE PERCUSSION MAC HIN

Claims.

This invention relates to pile hammers, earth rammers, concretebreakers, and like percussion machines (hereinafter referred to simplyas hammers) of the type which is operated as a fuel injection internalcombustion engine and which comprises a piston and piston rod structurestationary in relation to and supported by the object to be struck, anda cylinder which reciprocates longitudinally with respect to the pistonand piston rod structure and forms the ram that strikes the blows.

In known hammers of this type part of the delicate operating mechanismfor supplying'fuel is subject to severe shock and vibration because itis attached to a part of the hammer which either receives or strikes theblow.

The principal object of the invention is to reduce this shock andvibration on the operating mechanism by attaching it to a part of thehammer not receiving impact and removing said mechanism from the pointof impact by a distance greater than the length of stroke of the hammer.

Another object is to provide a hammer of the aforesaid type constructedto operate at will on the single-acting or double-acting principle.

A third object is to provide a hammer of the aforesaid type wherein anelectric ignition sparking plug is used in association with fuelinjection.

A fourth object is to provide a hammer of the aforesaid type which canbe adapted for extracting piles.

In accordance with the invention a hammer of the type firststated isprovided with a fuel injection pump mounted on the piston and piston rodstructure below the top of the piston and at a distance from the bottomof said structure greater than the length of the stroke of the cylinder,pump operating means mounted on said structure, and a member on thereciprocating cylinder co-acting with said means.

To enable single-action or double-action of the hammer at will alongitudinal slot or slots, greater in length than the length of strokeof the cylinder, may be provided in the cylinder to serve as inlet andexhaust ports to and from the lower chamber therein. Alternatively portsmay be provided in this chamber or a valve may be provided in the bottomof the piston.

In order to reduce cushioning of the blow of the ram due to the highcompression required for compression ignition, ignition may be effectedby an electric sparking plug used in conjunction with a fuel injector.

Adaptation for use as a pile extractor may be by altering the positionof the trip cam which operates the pump lever relative to the pile,which may be effected by inserting a distance piece under the bottom ofthe piston rod.

B way of example two hammers embodying constructional forms of theinvention will now be described with reference to the accompanyingdrawings.

Fig. 1 is a longitudinal section of a hammer in the plane I-I of eitherFig. 3 or Fig. 4.

Fig. 2 is a longitudinal section of the same hammer in the plane II-IIof either Fig. 3 or Fig. 4.

Fig. 3 is a cross section in the plane III-III of Fig. 1.

Fig. 4 is a plan on the plane IV-IV of Fig. 2.

Reference l denotes the hammer cylinder which surrounds the piston 2 andthe piston rod 3 and which forms the ram that reciprocates relative tothe piston. The piston rod rests on the pile or object to be struck andthus the piston remains stationary relative to the pile or object.

Mounted inside or attached to the piston is the operating mechanismcomprising fuel injectors 4 and 4a, fuel pumps 5 and 5a, and pump levers6 and 6a, which supply fuel from a fuel tank I through a pipe line 8 tothe upper and lower combustion chambers 9 and I0 respectively.Longitudinal slots II in the cylinder, greater in length than its lengthof stroke, serve as inlet and exhaust ports and allow for projection ofthe pump levers B and 6a, and for a detachable bracket [2 which supportsthe fuel tank. Trip cams l3 and I30. on the cylinder adjacent the slotsoperate the pump levers 6 and 6a respectively as the cylinderreciprocates. The length of stroke of the cylinder is controlled by amanually operated control lead l4 attached to the fuel pump.

[5 denotes an anvil which is attached to the pile by means of lugs l 6to provide additional reaction to the upward thrust when the hammer isused as a double-acting pile hammer. The anvil is non-rigidly attachedto the piston 2 and piston rod 3 by means of a stud l1 and a tie I8.

The operation of the hammer is as follows:

Single-action will be described first for clarity, and because this willbe the usual order in the case of pile driving where there may not besufficient reaction to the upward thrust of doubleacting until the pilehas developed some friction in the ground, and the length of stroke istherefore limited at the start of driving to prevent double-action,

As the cylinder or ram l falls to strike a blow air is entrapped in theupper chamber 9 when the upper ends of the slots ll pass over the wallof the piston 2 and this air is compressed. Towards the end of the blowthe trip cam l3 strikes the pump lever B which actuates the plunger ofthe fuel pump 5 to inject fuel into the upper chamber 9, and the mixtureof fuel and air in the said chamber ignites whereupon the cylinder orram I is again raised and the cycle repeats.

Double-action is brought about by increasing the length of stroke of thecylinder or ram I so that on the up stroke air is then entrapped in thelower chamber 10 when the lower ends of the slots I! pass over the Wallof the piston 2 and this air is compressed. Towards the end of the upstroke the trip cam 13a strikes the pump lever 6a. which actuates theplunger of the fuel pump 5a to inject fuel into the lower chamber I andthe mixture of fuel and air in said chamber ignites whereupon thecylinder is forced down and the cycle repeats.

The hammer may be started by raising the cylinder or ram I and dropping,and, in the case of electric ignition, by injecting a charge oflowflash-point fuel and igniting it, or by any of the other startingmeans known per se.

A sparking plug 15 may be mounted inside the piston and open through thepiston head to the upper combustion chamber 9, said plug being connectedby an electric lead extending through one of the slots ii in thecylinder to a magneto 20 attached to the piston and tripped by a boss orequivalent on the reciprocating cylinder or ram I. Instead of a magnetoan electric battery may be employed.

A duct 2! may be provided leading from the lower chamber 10 to a valve22 in the top of the cylinder 1 to allow some of the compressed air fromthe lower chamber I 0 to aid in scouring the upper combustion chamber 9.

The hammer may be adapted for use as a pile extractor by providing lugs23 on the cylinder to engage and strike upward blows on links attachedto the pile. The Cylinder or ram may be cushioned and prevented fromstriking a blow on the down stroke by altering the position of the tripcam !3 relative to the pile; this can be done by inserting a distancepiece 24 under the bottom of the piston rod 3.

Sealing rings are provided on the piston and in the bushing surroundingthe piston rod.

I claim:

1. In a hammer of the type which is operated as a fuel injectioninternal combustion engine and which comprises a piston and piston rodstructure stationary in relation to and supported by the object to bestruck, and a cylinder which reciprocates longitudinally with respect tothe piston and piston rod structure and forms the ram that strikes theblows, the combination of a fuel injection pump mounted on the pistonand piston rod structure below the top of the piston andat a distancefrom the bottom of said structure greater than the length of the strokeof the cylinder, said cylinder having a, longitudinal slot, pumpoperating means mounted on said structure and projecting through saidslot, a member on said reciprocating cylinder co-acting with said means,a fuel supply line to the pump passing through the slot in saidcylinder, 2. control lead for said fuel injection pump terminating atone end at a control position and extending into the slot in saidcylinder and terminating at the other end at said pump operating means.

2. A hammer according to claim 1, including an electric ignition meansfor controlling said pump operating means.

3. A hammer according to claim 1, including a distance piece insertedunder the bottom of the rod of the piston and the piston rod structure.

4. In a power driven hammer of the type which is operated as a fuelinjection internal combustion engine and which comprises a hammerincluding a piston and piston rod stationary in relation to andsupported by the object to be struck, and a reciprocating cylinder whichreciprocates longitudinally with respect to the piston and piston rodand constitutes a ram which strikes the impact blows, a mounting for afuel injection pump supported on a part of the hammer which isstationary and independent of any portion of the hammer which receivesor imparts impact blows, said mounting being disposed below the top ofthe piston and at a distance from the point of impact greater than thelength of the stroke of the cylinder, and a memher on the reciprocatingcylinder for actuating the pump.

5. In a power driven hammer of the type which is operated as a fuelinjection internal combustion engine and which comprises a hammerincluding a piston and piston rod stationary in relation to andsupported by the object to be struck, and a reciprocating cylinder whichreciprocates longitudinally with respect to the piston and piston rodand constitutes a ram which strikes the impact blows, the combination ofa fuel injection pump mounted on. the piston in a position below the topof the piston and at a distance from the point of impact greater thanthe length of the stroke'of the cylinder, and a member on thereciprocating cylinder co-acting with the said fuel injection pump.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,158,839 Pierce Nov. 2, 1915 2,093,634 Cordes Sept..21,193'72,140,205 Haage Dec. 13, .1938 2,167,983 Kiecksee Aug. v1, 19392,203,384 Douglas June 4, 1940 2,208,730 Pfeifier July 23, 19402,273,095 Fitch Feb. 17, 1942

